Pitched rigid frame structure

ABSTRACT

An improved pitched rigid frame structure in which an inside space is made lager than previous ones. The pitched rigid frame structure includes a pair of posts; diagonal beams extending from a post top of each post and joining to configure a pitched roof; an angle brace built between a point on a post and a point on a diagonal beam, the point on the post descending from a crossing point of the post and an axis line of the diagonal beam, the point on the diagonal beam heading from each post top to an apex of the pitched roof, and an inclined tension member built between a lower end of a compression member hanging from the apex of the pitched roof and the point on the diagonal beams building the angle brace.

TECHNICAL FIELD

The present invention relates to an improved pitched rigid frame structure in which an inside space is made larger than previous ones.

BACKGROUND ART

In order to construct a large inside space, a pitched rigid frame structure is adapted in which diagonal beams extending from each post top of a pair of posts are jointed to configure a pitched roof, and in which a horizontal tension member is built between the diagonal beams. The pitched rigid frame structure is made large by adapting a large sized member as the posts and the diagonal beams to enlarge an inside space. However, the large sized member costs more as a material cost. If a size of the member is enlarged, a stress applied to the post becomes large if a distance between the posts (more correctly, a distance between axis lines of the posts) is too large, and a bending moment applied to the posts is too large to build the pitched rigid frame structure.

Patent Document 1 discloses a pitched rigid frame structure in which diagonal beams extending from each post top of a pair of posts are jointed to configure a pitched roof, and in which an inclined tension member built between a lower end of a compression member hanging from an apex of the pitched roof and a point on a diagonal beam heading from a post top to the apex (Patent Document 1, Claim 1). According to the pitched rigid frame structure of Patent Document 1, posts and diagonal beams are configured with smaller sized members to reduce a material cost and a construction cost (Patent Document 1, [0039]) by lifting the compression member with the inclined tension member pulled outwardly by a bending moment of the diagonal beams, and by canceling out the bending moment with an inverse moment generated in the diagonal beams to enhance a structural strength (Patent Document 1, [0012])

PRIOR ARTS Patent Document

Patent Document 1: Japanese Patent Application Publication No. H08-189081

DISCLOSURE OF THE INVENTION Problem to be Solved by the Invention

Examples of a pitched rigid frame structure raised in Patent Document 1 have a distance (span) between the axis lines of posts up to 60 m. If the distance (span) between the axis lines of posts exceeds 60 m, large sized members have to be adapted even with the pitched rigid frame structure disclosed in Patent Document 1. If the distance (span) between the axis lines of posts exceeds 100 m, it is difficult to construct it because a stress applied to the posts becomes large and a bending moment applied to the diagonal beams becomes large too. The pitched rigid frame structure is superior in a point that no obstacles exist between the posts and a continuous inside space is provided. Therefore, if the distance (span) between the axis lines of posts is larger, it is more convenient. A rigid frame structure whose inside space is larger than the one disclosed in Patent Document 1 is studied.

Means to Solve the Problems

Provided is a pitched rigid frame structure including: a pair of posts having a truss structure, whose axis line being away at a distance of 80 m to 120 m; diagonal beams having a truss structure, extending from a post top of each post and joining to configure a pitched roof; an angle brace built over a point on a post and a point on a diagonal beam, the point on the post descending within 5 m from a crossing point of the post and an axis line of the diagonal beam, the point on the diagonal beam heading from each post top to an apex of the pitched roof, a horizontal distance from the axis line of the post being 3/40 to 4/40 of the distance between the axis lines of the pair of posts; and an inclined tension member built between a lower end of a compression member hanging from the apex of the pitched roof and the point on the diagonal beams building the angle brace or a point on the diagonal beam heading from the point to the apex. Height of the lower end of the compression member may be equal to or higher than the point on the post building the angle brace. The diagonal beams or the inclined tension member may be asymmetry with respect to left and right.

The bending moment applied to the diagonal beams becomes large in a pitched rigid frame structure whose distance (span) of axis lines of posts is large. A moment at an outer end (a moment at a connecting point at the post top which is lower end of the diagonal beams) and a moment (a moment at the apex of the pitched roof joining the diagonal beams) in the middle of the diagonal beams become small by receiving a vertical load at the apex of the pitched roof joining the diagonal beams with the inclined tension member intervening the compression member, and by the angle brace transmitting a vertical force at an end portion of the inclined tension member to the posts instead of transmitting it to the diagonal beams. The distance (span) of axis lines of posts is able to be made larger in the rigid frame structure of the present invention, exceeding the pitched rigid frame structure disclosed in Patent Document 1.

In order to make a distance (span) of axis lines of posts large, the point on the posts building the angle brace is at a point descending within 5 m from a crossing point of the post and an axis line of the diagonal beam (considering a thickness of the diagonal beams, the crossing point may be descend exceeding 5 m a little). The point on the diagonal beams building the angle brace is a point heading from each post top to the apex of the pitched roof, and a horizontal distance from the axis line of the post is 3/40 to 4/40 of the distance between the axis lines of the pair of posts. According to this, the moment at the outer end (the moment at the connecting point at the post top which is the lower end of the diagonal beams) and a moment (a moment at the pitched roof joining the diagonal beams) in the middle are made small to make it possible to make a distance (span) of axis lines of posts large.

If the distance (span) of axis lines of posts is large, the diagonal beams are possibly bowed, or the posts applied with an axial force of the angle brace are possibly horizontally deformed by a bending stress applying to the posts. The posts and the diagonal beams adapt a truss structure to enhance a stiffness of the posts and the diagonal beams. The truss structure is less expensive than a welded H-steel beam. If a stiffness of the similar extent as the welded H-steel beam is realized with the truss structure, it is advantageous that the truss structure is lighter than the welded H-steel beam. The truss structure can be configured, for example, by configuring a main material (an upper chord member and a lower chord member) or a lattice with H-steel beams, which are a standardized product.

Effects of the Invention

According to the pitched rigid frame structure of the present invention, a larger inside space is formed compared to the pitched rigid frame structure disclosed in Patent Document 1 to enhance an availability as a pitched rigid frame structure. The inside space can be made large by making the distance (span) of axis lines of posts large with the angle brace built between a point on a post and a point on a diagonal beam. The point on the post descends within 5 m from a crossing point of the post and an axis line of the diagonal beam. The point on the diagonal beam heads from each post top to an apex of the pitched roof. A horizontal distance from the axis line of the post is 3/40 to 4/40 of the distance between the axis lines of the pair of posts. By configuring the posts and the diagonal beams with the truss structure, a stiffness of the posts and the diagonal beams is enhanced, the distance (span) of axis lines of posts is made large up to 120 m, and a material cost and a construction cost are reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view illustrating an example of a pitched rigid frame structure applied with the present invention.

FIG. 2 is a partially magnified view illustrating a post and a diagonal beam having a truss structure used in the pitched rigid frame structure of the present example.

FIG. 3 is a schematic view illustrating an example of a pitched rigid frame structure applied with a prior invention.

FIG. 4 is a schematic view illustrating a basic pitched rigid frame structure.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

An embodiment for carrying out present invention is explained with reference to Figs. In a pitched rigid frame structure 1 configured by applying the present invention, as illustrated in FIG. 1, a pitched roof is configured by joining diagonal beams 12, 12 extending from respective post tops 111, 111 of a pair of posts 11, 11. An angle brace 13 is built between a point 112 on the post 11 descending from each post top 111 and a point 121 on a diagonal beam 12 heading from each post top 111 to an apex 125 of the pitched roof. An inclined tension member 15 is built between a lower end 141 of a compression member 14 hanging from the apex 125 of the pitched roof and the point 121 on the diagonal beams 12 building the angle brace 13.

The pitched rigid structure 1 assumes a size configuring an inside space in which the distance (span) S of axis lines 113 of posts is 120 m, and a height at the lower end 141 of the compression member 14 (an equivalent height) is approximately 20 m. The present invention can be applied to a pitched rigid structure 1 smaller than above mentioned size. For example, it is applied to the one having the distance S of axis lines 113 of posts 11 is 80 m and the equivalent height is 10 m. If the distance S of axis lines 113 of post 11 becomes small or the equivalent height becomes small, according to the pitched rigid structure applied with the present invention, a size of materials to be used can be made small and light.

To prevent the diagonal beam 12, which is long, from bowing and the posts 11 from being horizontally deformed by an axial force of the angle brace 13, as illustrated in FIG. 2, the truss structure is preferably adapted in the pitched rigid frame structure 1 of the present invention. The posts 11 having the truss structure is configured by building a H-steel beam as a lattice at an angle between H-steel beams as left and right main materials. An intermediate line between the H-steel beams 114, 114 functioning as left and right main materials is an axial line 113. The diagonal beam 12 having the truss structure is configured, for example, by building a H-steel beam 124 as a lattice at an angle between H-steel beams as upper and lower main materials 123, 123. An intermediate line between the H-steel beams 123, 123 as left and right main materials is an axial line 122.

Since the post 11 and the diagonal beam 12 are standardized product and are configured by easily obtainable H-steel beams, it is easy to design or inexpensive to manufacture. Although a welded H-steel beam may be used instead of the posts 11 and the diagonal beam 12 having the truss structure of the present example, material cost rises if the welded H-steel beam, as it is called irregular products, is adapted. If the distance S is same, a grade can be made lower than a prior similar pitched rigid frame structure (for example, see FIG. 3 shown later) to reduce the material cost, by reducing a moment on outer end of the diagonal beam and a moment in the middle to make the distance S of the axis lines 113, 113 of the posts 11, 11 large. According to this, it is understood that the post 11 and the diagonal beam having the truss structure are more preferable than the welded H-steel plate rising the material cost.

A point 112 on the post building the angle bracket 13 is a point descending at an amount ΔH set within 5 m or below from crossing point of an axial line 1113 of the post 11 and an axial line 122 of the diagonal beam 12. ΔH is set so that an equivalent height (height at the lower end 141 of the compressing member 14) as the pitched rigid frame structure becomes higher than the point 112 on the post building the angle bracket 13. The point 121 on the diagonal beams 12 building the angle brace 13 is a the point heading from a post top 111 to an apex 125 of the pitched roof, and a horizontal distance from the axis line 113, 113 of the post 11, 11 is ΔS set within 3/40 to 4/40 between the distance of the axis lines of the pair of posts. The point 121 on the diagonal beams 12 building the angle brace 13 and the point on the diagonal beams 12 building the inclined tension member 115 correspond each other in the present example.

EXAMPLES

Stress values applied to the posts 11, 21, 31 and the diagonal beams 12, 22, 32 are calculated and compared in case the vertical load 10 kN/m is applied to the respective pitched roofs of the pitched rigid frame structure 1 applied with the present invention (Example 1 to Example 3, see FIG. 1), the pitched roof structure 2 (Comparative Example 1 to Comparative Example 3, see FIG. 3) applied with the prior invention (the invention disclosed in Patent Document 1 (Japanese Patent Application Publication No. H08-189081)), conventional and basic pitched rigid frame structure 3 (Comparative Example 4 to Comparative Example 6, see FIG. 4).

In the pitched roof structure 2 applied with the prior invention, the inclined tension member 25 is built between a lower end 241 of a compression member 24 hanging from the apex 225 of the pitched roof joining the diagonal beams 22, 22 extending from each post tops 211, 211 of the pair of posts 21, 21 and a point 221 on the diagonal beams 22 heading from the post top 211 to the apex 225. In the conventional and basic pitched rigid frame structure 3, the pitched roof is configured by joining the diagonal beams 32, 32 extending from each post top 311, 311 of the pair of posts 31, 31.

In Example 1, Comparative Example 1, and Comparative Example 2, the distance S=120 m. Height of the posts 11, 21, 31 is 25 m. Height of the apexes 125, 225, 325 of the pitched roof is 34 m. Height of the lower end 141 of the compression members 14, 24 used in Example 1 and Comparative Example 1 is equal to the equivalent height=20 m. Horizontal distance ΔS of the angle brace 13 used in Example 1 is 12 m. Vertical distance ΔH is 5 m. Lower end of the compression member 14 in Example 1 and a point 112 on the post 11 building the angle brace 13 are made at the same height.

In Example 2, Comparative Example 2, and Comparative Example 4, the distance S=100 m. Height of the posts 11, 21, 31 is 25 m. Height of the apexes 125, 225, 325 of the pitched roof is 20 m. Height of the lower end 141 of the compression members 14, 24 used in Example 2 and Comparative Example 2 is equal to the equivalent height=20 m. Horizontal distance ΔS of the angle brace 13 used in Example 1 is 10 m. Vertical distance ΔH is 5 m. Lower end of the compression member 14 in Example 2 and a point 112 on the post 11 building the angle brace 13 are made at the same height.

In Example 3, Comparative Example 3, and Comparative Example 6, the distance S=80 m. Height of the posts 11, 21, 31 is 25 m. Height of the apexes 125, 225, 325 of the pitched roof is 31 m. Height of the lower end 141 of the compression members 14, 24 used in Example 3 and Comparative Example 3 is equal to the equivalent height=20 m. Horizontal distance ΔS of the angle brace 13 used in Example 3 is 8 m. Vertical distance ΔH is 5 m. Lower end of the compression member 14 in Example 3 and a point 112 on the post 11 building the angle brace 13 are made at the same height.

TABLE 1 Distance S between Pitched rigid frame structure Pitched rigid frame structure Conventional and basic axis lines of a applied with the present applied with the prior pitched rigid frame pair of posts invention (see FIG. 1) invention (see FIG. 3) structure (see FIG. 4) S = 120 m Example 1 Comparative Example 1 Comparative Example 4 Post M = 4582(52%) Post M = 4588(55%) Post M = 8889 (Post top M = 2608 as a Post N = 607(—) Post N = 607 reference) Diagonal beam M = 4859 (55%) Diagonal beam M = 8889 Post N = 607(—) Diagonal beam N = 400(55%) Diagonal beam N = 726 Diagonal beam M = 2608 (29%) Diagonal beam N = 368(51%) S = 100 m Example 2 Comparative Example 2 Comparative Example 5 Post M = 3268(51%) Post M = 4004(63%) Post M = 6359 (Post top M = 1889 as a Post N = 506(—) Post N = 506 reference) Diagonal beam M = 4004 (59%) Diagonal beam M = 6359 Post N = 506(—) Diagonal beam N = 332(65%) Diagonal beam N = 512 Diagonal beam M = 1889 (30%) Diagonal beam N = 253(49%) S = 80 m Example 2 Comparative Example 3 Comparative Example 6 Post M = 1938(47%) Post M = 2146(52%) Post M = 4145 (Post top M = 777 as a Post N = 404(—) Post N = 404 reference) Diagonal beam M = 2146 (52%) Diagonal beam M = 4145 Post N = 404(—) Diagonal beam N = 194(58%) Diagonal beam N = 334 Diagonal beam M = 777 (19%) Diagonal beam N = 216(65%) Moment M: kN · m, Axial Force N: kN Post M is a moment at a point on post building an angle brace

Calculated result is shown in the table 1. In the table 1, values in brackets is a proportion (in percentage) of Examples 1 to 3 or Comparative Examples 1 to 3 with respect to a standard (100%) of Comparative Examples 4 to 6 (conventional and basic pitched rigid frame structure 3). Moment M and axial force N applied to the posts 21 and the diagonal beam 22 are small in the pitched rigid structure 2 applied with the prior invention too when they are compared to the conventional and basic pitched rigid frame structure 3. Moment M and axial force N applied to the posts 21 and the diagonal beam 22 are similar or smaller in the pitched rigid structure 1 applied with the present invention when they are compared to the pitched rigid frame structure 2 applied with the prior invention. It is understood that the pitched rigid frame structure according to which broad room space is formed can be built by utilizing the present invention.

Next, based on the stress shown in the table 1, weight of steel beam only in the pitched roofed structures 1, 2, 3 is compared. Material constitution of Examples 1 to 3 and Comparative Examples 1 to 6 is selected. For comparison, all of the posts 11, 21, 31 and the diagonal beams having truss structure combining H-steel beams are used in Examples 1 to 3 and Comparative Examples 1 to 6. In the truss structures of Example 1, Example 2, Comparative Example 1, Comparative Example 2, Comparative Example 4, and Comparative Example 5, a span between webs of main material is 3.0 m. In the truss structures of Example 3, Comparative Example 3, and Comparative Example 6, a span between webs of main material is 2.0 m. In Examples 1 to 3 and Comparative Examples 4 to 6, the angle brace 13, the compression members 14, 24, and the inclined tension members 15, 25 are circular steel pipe.

TABLE 2 Distance S between Pitched rigid frame structure Pitched rigid frame structure Conventional and basic axis lines of a applied with the present applied with the prior pitched rigid frame pair of posts invention (see FIG. 1) invention (see FIG. 3) structure (see FIG. 4) S = 120 m Example 1 Comparative Example 1 Comparative Example 4 Post and diagonal beam: truss Post and diagonal beam: truss Post and diagonal beam: truss structure structure structure (Distance between webs of main (Distance between webs of main (Distance between webs of main (material is 3.0 m) material is 3.0 m) material is 3.0 m) Main material H-350 × 350 × 12 × 19 Main material: H-400 × 400 × 13 × 21 Main material: H-414 × 405 × 18 × 28 Lattice: H-200 × 200 × 8 × 12/post Lattice: H-175 × 175 × 7.5 × 11 Lattice: H-200 × 200 × 8 × 12 H-175 × 175 × 7.5 × 11/diagonal beam Inclined tension member: Ø 355.6 × 12 →weight = 87.5 kg/m² Angle brace: Ø 355.6 × 12 →weight = 81.3 kg/m²(92%) Δ S = 12 m, Δ H = 5 m Inclined tension member: Ø 216.3 × 8 →weight = 86.9 kg/m²(76%) S = 100 m Example 2 Comparative Example 2 Comparative Example 5 Post and diagonal beam: truss Post and diagonal beam: truss Post and diagonal beam: truss structure structure structure (Distance between webs of main (Distance between webs of main (Distance between webs of main material is 3.0 m) material is 3.0 m) material is 3.0 m) Main material: H-300 × 300 × 10 × 15 Main material: H-300 × 305 × 15 × 15 Main material: H-400 × 400 × 13 × 21 Lattice: H-200 × 200 × 8 × 12/post Lattice: H-175 × 175 × 7.5 × 11 Lattice: H-175 × 175 × 7.5 × 11 H-150 × 150 × 7 × 10/diagonal beam Inclined tension member: Ø 318.5 × 7 →weight = 73.6 kg/m² Angle brace: Ø 318.5 × 9 →weight = 57.7 kg/m²(80%) Δ S = 10 m, Δ H = 5 m Inclined tension member: Ø 216.3 × 8 →weight = 51.8 kg/m²(70%) S = 80 m Example 3 Comparative Example 3 Comparative Example 6 Post and diagonal beam: truss Post and diagonal beam: truss Post and diagonal beam: truss structure structure structure (Distance between webs of main (Distance between webs of main (Distance between webs of main material is 2.0 m) material is 2.0 m) material is 2.0 m) Main material: H-250 × 250 × 9 × 14 Main material; H-300 × 305 × 15 × 15/post Main material: H-350 × 350 × 12 × 19 Lattice: H-150 × 150 × 7 × 10 H-300 × 300 × 10 × 15/diagonal beam Lattice: H-175 × 175 × 7.5 × 11 Angle brace: Ø 267.4 × 8 Lattice: H-175 × 175 × 7.5 × 11 →weight = 67.1 kg/m² Δ S = 8 m, Δ H = 5 m Inclined tension member: Ø 216.3 × 8 Inclined tension member: Ø 190.7 × 7 →weight = 58.6 kg/m²(87%) →weight = 45.4 kg/m²(65%)

As it is apparent from table 2, in the pitched rigid frame structure 2 applied with the prior invention, required weight of steel beam is reduced to 92% (Comparative Example 1), 80% (Comparative Example 2), or 87% (Comparative Example 3) compared to the conventional and basic pitched rigid frame structure 3. It is shown that it is reduced by approximately 8% to 20%. This means that if all of the posts 21, 31 and the diagonal beams 22, 32 are configured by the same truss structure, material cost is reduced by approximately 8% to 20% to build the pitched rigid frame structure 2 applied with the prior invention when it is compared to the conventional and basic pitched rigid frame structure 3.

In the pitched rigid frame structure 1 applied with the present invention, required weight of steel beam is reduced to 76% (Comparative Example 1), 70% (Comparative Example 2), or 65% (Comparative Example 3) compared to the conventional and basic pitched rigid frame structure 3. It is shown that it is reduced by approximately 24% to 35%. This means that if all of the posts 11, 31 and the diagonal beams 12, 32 are configured by the same truss structure, material cost is reduced by approximately 24% to 35% to build the pitched rigid frame structure 1 applied with the prior invention when it is compared to the conventional and basic pitched rigid frame structure 3.

Further, in the pitched rigid frame structure 1 applied with the present invention, it is shown that required weight of steel beam is reduced by approximately 15% on average when it is compared with the pitched rigid frame structure 2 applied with the prior invention. According to the pitched rigid frame structure 1 of the present invention, required weight of steel beam is the smallest among the prior invention and conventional one. It is inexpensively built by reducing a material cost. According to the present invention, room space of the pitched rigid frame structure is made large. If the room space is same, the pitched rigid frame structure is more inexpensively built than previous one.

REFERENCE NUMERALS

-   1 pitched rigid frame structure -   11 post -   111 post top -   112 point on post -   113 axial line of post -   114 H-steel beam of main material -   115 H-steel beam of lattice -   12 diagonal beam -   121 point on diagonal beam -   122 axial line of diagonal beam -   123 H-steel beam of main material -   124 H-steel beam of lattice -   125 apex of pitched roof -   13 angle brace -   14 compression member -   141 lower end of compression member -   15 inclined tension member -   2 pitched rigid frame structure -   21 post -   211 post top -   22 diagonal beam -   221 post top -   225 apex of pitched roof -   24 compression member -   241 lower end of compression member -   25 inclined tension member -   3 pitched rigid frame structure -   31 post -   311 post top -   32 diagonal beam -   325 apex of pitched roof -   S distance between axis lines of posts -   ΔS horizontal distance between axis lines of posts -   ΔH vertical distance from crossing point of post and axial line of     diagonal beam 

1. A pitched rigid frame structure comprising: a pair of posts having a truss structure, whose axis line being away at a distance of 80 m to 120 m; diagonal beams having a truss structure, extending from a post top of each post and joining to configure a pitched roof; an angle brace built between a point on a post and a point on a diagonal beam, the point on the post descending within 5 m from a crossing point of the post and an axis line of the diagonal beam, the point on the diagonal beam heading from each post top to an apex of the pitched roof, a horizontal distance from the axis line of the post being 3/40 to 4/40 of the distance between the axis lines of the pair of posts, and an inclined tension member built between a lower end of a compression member hanging from the apex of the pitched roof and the point on the diagonal beam building the angle brace or a point on the diagonal beam heading from said point to the apex. 